Abstract: The deep roadway with broken surrounding rock has problems such as insufficient strength of surrounding rock, serious floor heave, etc. It is urgent to strengthen the surrounding rock with effective support means. With the help of COMSOL numerical simulation software, the paper constructs the grouting diffusion model of roadway coupling grouting reinforcement, takes the pressure iso-surface as the grouting diffusion index, obtains the grouting diffusion range under different grouting reinforcement methods, and imports the obtained grouting diffusion range model into 3DEC to study the grouting reinforcement characteristics. After that, taking the surrounding rock reinforcement of belt roadway in 12101 working face of Wangjialing Coal Mine as the engineering background, the different reinforcement effects of the original support mode of belt roadway and deep shallow hole high and low pressure coupling grouting reinforcement are studied. The results show that the grouting diffusion range division method is reasonable and can better meet the engineering practice; compared with the original support method, the roadway safety has been greatly improved by using the coupling grouting support method.